A "karaoke" device is a digital storage media playback device, typically a laser disc player or CD-ROM drive, used for amusement purposes. The karaoke device plays a musical accompaniment to a song, but not the vocal accompaniment (or at least not the lead vocal accompaniment). Usually, this is achieved by recording a specific arrangement of the song that lacks one or more vocal accompaniments. A selected song is played back and an individual provides a live version of the vocal accompaniment. Typically, the individual providing the vocal accompaniment is an amateur singer who has difficulty maintaining correct pitch for the vocal accompaniment. A video presentation, including the text of the lyrics, is also typically generated by the digital storage media playback device from the digital storage medium.
In the karaoke art, processors exist for correcting the vocal pitch of an amateur signer. Typically, these processors employ one of two approaches whereby the singer's pitch is corrected to the nearest semitone or to the nearest note within a given scale. Both of these techniques have disadvantages. In the "nearest semitone" approach, the singer's pitch must be within a half semitone of the correct pitch. However, this is difficult for an amateur singer to achieve. In this approach, if the signer's pitch is off by more than a half semitone, the correction process tends to produce a vocal signal that deviates more from the correct pitch than the original uncorrected vocal signal. In the "nearest tone" approach, the singer must specify the scale in which the singer will sing. This is generally impractical in the context of an amusement device for amateurs. Moreover, this presents a problem if the vocal accompaniment changes key during the song. Furthermore, the pitch of the singer's vocal signal must still be closer to the correct note than any other note in the scale in order to produce a vocal signal that is closer to the correct pitch than more deviant. Again, this is not always the case for an amateur singer.
It is an object of the present invention to overcome the disadvantages of the prior art.